In practice, methods of this type are used to produce by press hardening, for example from manganese-boron steels, components having a uniform hardening profile of up to 1,500 MPa. Owing to the low ductility remaining in such steels after the hardening process, components made of steels of this type are for this purpose conventionally first preformed, then heated to austenitising temperature and subsequently cooled rapidly in a mould under elevated pressure. In addition to their high hardness, parts obtained in this way display good dimensional stability.
A press hardening method forming part of the above-mentioned prior art is known, for example, from DE 103 41 867 A1. According to this method, a hardened sheet metal profile can be produced in that an intermediate form is first shaped from a sheet metal blank, this sheet metal profile is then heated to hardening temperature and in that finally the heated sheet metal profile is purposefully cooled in a device resembling a deep-drawing tool under the action of a predetermined pressing means. The intermediate form produced in the first step of the method thus approximately corresponds to the final form of the component to be produced.
The device used for carrying out the known method has channel-like cooling assemblies which, depending on the respective heat to be removed, are flushed with oil, water, ice water or saline solution. The cooling assemblies can be controlled separately of one another in order to form in the finished component zones having differing degrees of hardness.
Despite the advantages achieved in this way with the method known, for example, from DE 103 41 867 A1, there is demand for a method which can be carried out in a simplified manner in terms of production and allows components which are shaped from a sheet metal element and have precisely predeterminable zones having differing material properties to be produced.